Pd-loaded unique urchin-structured GaO for selective CO photoreduction to CH

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-09, Vol.12 (36), p.24328-24338
• Main Authors: Qiu, Wei, Lu, Pengjian, Kuang, Xiaoxu, Li, Baowen, Tu, Rong, Zhang, Song
• Format: Article
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta04038d

The effectiveness of photogenerated carrier separation and the restricted number of active sites result in unsatisfactory CO 2 photoreduction efficacy. Furthermore, the CO 2 photoreduction process always shows the drawback of low product selectivity. Herein, a unique urchin-structured Ga 2 O 3 -based photocatalyst with Pd loading was designed and the relationship between the loading amount and the optimal catalytic performance was investigated. Results show that Ga 2 O 3 synthesized at 90 °C with 2% Pd loading amount (2%Pd/Ga 2 O 3 -90) gives an excellent yield of up to 107.48 μmol g −1 h −1 and 99.5% selectivity of CH 4 . The larger specific surface area (44.7 m 2 g −1 ) of Ga 2 O 3 prepared at 90 °C (Ga 2 O 3 -90) can provide more active sites, simultaneously, the highly dispersed Pd nanoparticles act as both active sites for CO 2 adsorption and activation and as centers for electron capture to facilitate the photogenerated carrier separation effectively. Furthermore, the in situ DRIFTS spectra and CO adsorption isotherm of 2%Pd/Ga 2 O 3 -90 confirm the presence of key intermediates such as *CO, and *CHO, indicating that CO can be captured by Pd and further protonated, thereby exhibiting 99.5% selectivity of CH 4 . This work provides valuable insights into the preparation of catalysts with a high specific surface area and highly selective CO 2 photoreduction to CH 4 . An innovative urchin-structured Ga 2 O 3 -based photocatalyst with a high specific surface area and highly selective CO 2 photoreduction to CH 4 is designed by constructing a dual microemulsion mixed system.